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Thread: MISCELLANEOUS QUESTIONS

  1. #1
    Senior Member dr_bubo's Avatar
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    MISCELLANEOUS QUESTIONS

    To decrease the topics I opened this miscellaneous questions topic so I put all my questions regarding cure , here.

    I found this article. Can you professor Young explain what this cyclic AMP is and can it be tested on humans? Also what is your overall opinion about this article.
    Thank you
    Bubo
    ----
    Spinal Cord Repair May Be Possible

    Scientists announced they have figured out a new way to get nerve cells to regenerate in the laboratory and have come one step closer to being able to repair spinal cord injuries -- although that prospect remains years away.

    "For the first time in history there is some optimism that we may be able to get functional recovery of spinal cord injuries," Ronald L. Schnaar, co-author of the study and professor of pharmacology and of neuroscience at Johns Hopkins University, told United Press International. "Whether it's this decade or next decade, I think we'll begin to see this knowledge turned into therapies."

    Schnaar and colleagues at the University of Hamburg, Germany, discovered how to modulate a molecular signal that inhibits the regeneration of nerve cells after they are damaged.

    "Whenever there is an injury to the central nervous system including the spinal cord, molecules remain which instruct nerve cells (not to regenerate)," Schnaar explained. By blocking these molecules or the nerve cell receptors they bind to, "we might be able to allow nerve cells to regenerate."

    One of these inhibiting molecules is called MAG, or myelin associated glycoprotein. Rat nerve cells will grow when placed in a culture dish, but if MAG is added it stops them cold, Schnaar said.

    Schnaar's team found blocking the nerve cell receptors that MAG binds to -- either with an enzyme that shuts off the binding site or an antibody that prevents MAG from binding altogether -- they could get the nerve cells to grow again.

    The findings "point the way to a potential way to enhance nerve regeneration," Schnaar said, cautioning, "Our studies have no immediate medical application, and I think it will be some time before these therapies get tested in humans."

    The findings with MAG mirror studies of two others inhibitor molecules similar to MAG. The molecules, called Nogo and CSPG, or chondroitin sulfate proteoglycan, also can be blocked, allowing nerve cells to regrow after they are damaged.

    "The hope is that by combining one or more of these reversal techniques we can take the brakes off and get nerve cells to regrow," Schnaar said.

    Studies in animals have looked promising and have generated "modest recovery," he said. "For people with spinal cord injury, every modest amount of increase would be important."

    Marie T. Filbin, a professor of neurobiology at Hunter College in the City University of New York, downplayed the findings.

    "It's an interesting hypothesis. However, a lot more work needs to be done to show that (interfering with MAG receptors causes) inhibition," said Filbin, who recently published two papers in the journal Neuron showing the injection of a molecule called cyclic AMP enabled rat spinal cords to regenerate after being cut.

    Filbin's research suggests MAG is binding to something else on the nerve cells and soon will publish research showing just that, she told UPI.

    Schnaar would not provide a timeline for when nerve regeneration therapies might be used in humans, but he said, "People in the field are talking 5 to 10 years. But who knows, it could be faster, it could be slower."

    The study appears in this week's Proceedings of the National Academy of Sciences.
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  2. #2
    Bubo, if you do a search for Schnaar you will find many posts on this site. I don't think that there is any therapy for spinal cord injury that has not been discussed or at least mentioned on this site.

    The original paper by Schnaar is located at the following topic and is extensively discussed.

    Likewise, cAMP has also been discussed. Can I suggest that you do a search for "filbin and cAMP"?

    wise

  3. #3
    Senior Member dr_bubo's Avatar
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    Dear Professor Young,

    Can you tell me what are axons? I mean what they are made of? Are thet bridges of cells or bridges of molecules?

    I am asking it because there is now a new Hungarian machine which can weld and cut material on nanolevel, I mean down to atom size.
    The article is in Hungarian but pics can also be found here:
    http://index.hu/tech/tudomany/nanotech0617/
    if u click on any picture there a picture show loads.

    I wonder if it would be possible to "engineer" the damaged spinal cord, I mean to open it and make the axon connections by engineering, with nanomachines...
    of course one must know which cells to connect.. I dunno if anyone knows what are the correct connections in a healthy spinal cord.
    Does anyone know?
    Thanks
    Bubo

  4. #4
    Bubo,

    Axons are a specific type of cell. Lots of them are connected together via synapses [and dendrites] until they reach the muscle they affect. Tiny nanomachines could be made that stimulate a cell to release the proper proteins and/or growth factors so that new connections are formed.

    -Steven

  5. #5
    Bubo,

    Axons are not cells. They are part of cells, i.e. the long processes that neurons use to connect with each other and with muscles. For example, a neuron in the cortex of the brain will send an axon down to the spinal cord after crossing over the midline and go all the way down the spinal cord to connect with motoneurons at various levels of the spinal cord. This is called the corticospinal tract. There are many descending tracts from different parts of the brain, connecting with interneurons and motoneurons in the spinal cord. Interneurons are those neurons that send axons to other neurons. Motoneurons send axons that go out the cord to connect with muscles. Some interneurons are inhibitory.

    When axons are injured, the part of the axon that is separated from the cell body will die. However, the neuron that gave rise to the axon continues to live. The axon that is still connected to the neuron also lives. In order to regenerate, that axon must grow across the injury site and all the way back to the original neuron(s) that it connected to. Specificity of connection is desirable but not absolutely necessary. Axons are not like wires. It is not a matter of reconnecting them. They have to regrow.

    Wise.

  6. #6
    Senior Member dr_bubo's Avatar
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    Dear Professor Young,

    You wrote: "Axons are not cells"

    Steven Edwards wrote: "Axons are a specific type of cell"

    So what are axons? I mean what are they not what their functions are. Axons are connected small cells or connected molecules?
    Whena neuron makes an axon, does it "give birth" to many small cells which form axon or axons are created from something else, and neurons only promote the growth? Where do axons origin? From the neuron or from the intercellar matter?
    Thanks
    Bubo

  7. #7
    Bubo, an axon is a long process that is part of a neuron. Most cells contain a nucleus and a cell body. The inside of the axon is composed of axoplasm which is continuous with the cytoplasm of a neuron. If an axon is cut, the part of the axon that has been separated from the cell body dies. It does not die immediately but it will die. Although there have been some reports that an axon that has been cut can perhaps be rejoined rapidly and still function, most of this data comes from invertebrate nervous systems and there is some controversy whether this can happen in mammalian axons. What I am saying here is common knowledge. Why don't you do a quick search of internet for axon and look for the definition of axon. Wise.

  8. #8
    Oh. My. God. :jaw drops... quickly:

    Thank you so much for posting that, Wise. I was under the impression -- I have no idea where it came from -- that axons were seperate cellular extensions that connected to the neurons.

    Again, thanks for correcting me. Now it's time to reread some papers and put everything in the proper perspective.

    Bubo, check out this site for some information.

    -Steven

  9. #9
    Steven, I am so glad that you did post. I am just beginning to learn not to assume that people know. Perhaps I need to learn more. How many people here believe the following?

    1. Axons are like wires and can be reconnected to function again.

    2. The spinal cord below the injury site dies.

    3. Stem cells replace axons.

    4. Axons from the brain connect directly to muscles.

    Wise.

  10. #10
    [QUOTE]
    1. Axons are like wires and can be reconnected to function again.

    Dr Young,
    If axons can not be reconnected as a result of regenerative therapies. How they will be able to grow to the correct connection. What will be their guidance. Some of them are several feet long, if am correct. How they can find space in a spinal cord to grow all the way down to the right connection.
    That is what I cannot understand. Thanks.

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